
Social security contributions for agencies in Lengwil explained simply
Whether you run a Sàrl, an SA or a sole proprietorship in Lengwil, social security contributions eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
The Swiss legal frame for social security contributions
Responsibility for the books is personal: in an SA, organising the accounting is one of the board's non-transferable duties (art. 716a CO); in a Sàrl, the managing directors carry the same duty. Outsourcing the execution never transfers that underlying responsibility, including for a company based in Lengwil.
Also worth knowing: accounts may be drawn up in the currency most relevant to the business; if that is not the franc, values must additionally be stated in CHF (art. 958d para. 3 CO). Internationally active companies gain books that match their economic reality.
Outsource social security contributions or keep it in-house?
A fiduciary's cost depends first on the quality of the data received: digitised, filed, reconciled documents are processed fast; a box of loose receipts is billed by the hour. Improving the internal preparation of social security contributions lowers fees more surely than any negotiation.
A business in Lengwil can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — social security contributions splits very well.
A Swiss SME's accounting calendar
An accounting calendar only lives if it is shared: owner, in-house bookkeeper and fiduciary must see the same deadlines and the same status — the rule holds for every SME in Lengwil.
For a business in Lengwil, an isolated delay can be caught up; a structural delay is paid in interest, fines and stress. The difference between the two: a system, not good intentions.

Digitalising social security contributions: what actually works
Artificial intelligence has changed the economics of social security contributions: automatic invoice reading reaches recognition rates that make manual entry marginal, and posting suggestions learn from corrections. The accountant does not disappear — the job shifts from data entry to control and advice.
The winning pair for social security contributions: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.
Lengwil: what changes, what does not
Lengwil (postal code 8574, canton Thurgau) applies the same federal rules as the rest of the country: what changes in Lengwil are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Lengwil: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 8574 changes nothing about those rules, only the sender's address.
Frequently asked questions
When must a business register for VAT?
As soon as its worldwide annual turnover reaches CHF 100,000 (CHF 250,000 for non-profit sports or cultural associations). Below that, voluntary registration remains possible and often makes sense to reclaim input VAT on investments. The threshold is federal: it applies in Lengwil as everywhere in Switzerland.
Can social security contributions be automated with AI?
Largely, yes: automatic document reading, posting suggestions, bank reconciliation via QR references and VAT exports. Human approval remains essential — AI prepares, the professional checks. That is exactly how MyFiducia.ai approaches social security contributions.
How long must records related to social security contributions be kept?
Ten years from the end of the financial year concerned (art. 958f CO). Electronic retention is permitted if the integrity and readability of the records are guaranteed — a serious digital archive validly replaces paper binders. A business in Lengwil can therefore archive fully digitally.
What is the difference between a limited and an ordinary audit?
The ordinary audit applies to companies exceeding, for two consecutive years, two of three thresholds: CHF 20 million balance sheet total, CHF 40 million revenue, 250 full-time positions. Others fall under the limited audit, and those with no more than ten full-time positions on annual average can opt out with all shareholders' consent. These federal thresholds do not depend on the registered seat — in Lengwil as anywhere.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates social security contributions for businesses in Lengwil: AI-read documents, posting suggestions, VAT and exports ready for your fiduciary. Try the platform or browse our other guides.
The application is operated in French.